1. Field of the Invention
The present invention relates to a hollow actuator with a built-in reduction gear.
2. Description of the Related Art
As disclosed in Japanese Unexamined Patent Application Publication No. 2002-315261, in a hollow actuator with a built-in reduction gear, a motor hollow shaft is attached while penetrating through the inside of a hollow reduction gear, and an open portion of the reduction gear is sealed with oil seals to isolate the open portion from the outside.